Lower alkanoyl esters of 11-oxygenated androst-4-ene-3beta, 17beta-diols and intermediates thereto



United States Patent F The present invention is concerned with 3,11,17-trisoxygenated androstane derivatives and, more particularly, with ll-keto and llB-hydroxy derivatives of optionally l7-alkylated 35,17fi-bisoxygenated androst-4-enes wherein one or both of the 3/3 and 17B substituents is an acyloxy function. These compounds are conveniently depicted by the following structural formula OR CH wherein R and R can be hydrogen or a lower alkanoyl radical, X represents hydrogen or a lower alkyl radical, and Z is either a carbonyl or ,B-hydroxymethylene group.

The lower alkanoyl radicals designated by R and R in the foregoing representation include acetyl, propionyl, butyryl, valeryl, caproyl, and the branched-chain isomers thereof. Examples of the lower alkyl radicals encompassed by the X term are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, tert-pentyl, and hexyl.

The compounds of the present invention can be manufactured by reaction of the corresponding hydroxy substances with a suitable acylating agent. Such reagents are the anhydrides or halides of lower alkanoic acids. Particularly suitable halides are the alkanoyl chlorides. This acylation process is preferably conducted in the presence of an alkaline catalyst such as pyridine, triethylamine, etc. That process is specifically illustrated by the reaction of 3B,l7,3-dihydroxyandrost-4-en-1l-one with acetic anhydride and pyridine to alford 31?,17fi-dihydroxyandrost-4- en-l l-one 3,l7-diacetate and also by the reaction of androst-4-ene-3B-1113,17fl-triol with propionic anhydride, resulting in androst-4-ene-3fi,115,175-triol 3,17-dipropionate. It is apparent that the ll-hydroxy group remains unaffected in the instant process.

A process particularly suitable for the preparation of the l7-monoacyloxy compounds of this invention involves reduction of the corresponding 17- monoacyloxyandrost- 4-ene-3,1l-diones. A relatively short reaction time and minimum amount of reagent results in preferential reduction of the 3-keto group. Thus, for example, 17B-hydroxyandrost-4-ene-3,l l-dione 17-acetate is stirred With lithium tri-(tertiary-butoxy) aluminum hydride in tetrahydrofuran at room temperature for about 2 hours to afford 3,8,17,8- dihydroxyandrost-4-en-1l=one l7-acetate. When excess reagent is used and the reaction time is appreciably increased, reduction occurs at both the 3 and 11 positions. Typically, the aforementioned 17,8-hydroxyandrost-4-ene- 3-11-dione l7-acetate is stirred with excess lithium tri- (tertiary-butoxy) aluminum hydride in tetrahydrofuran for about 48 hours at room temperature to yield androst- 4-ene-3 8,11/3,17/3-triol 17-acetate.

The aforementioned 17-monoacyloxy compounds can serve as starting materials for the preparation of the instant 3,17-diacyloxy derivatives wherein the acyl groups 3,210,392 Patented Oct. 5, 1965 are dissimilar. The reaction of androst-4-ene-3,l3,115,17/3- triol 17-acetate, for example, with propionic anhydride and pyridine results in androst -4-ene-3/3,l1,8,17fi-triol 17- acetate, 3-propionate.

The l7ot-alkylated compounds of this invention are obtained by a two-step route utilizing 17ot-alkyl-l1fi,17[i-dihydroxyandrost-4-en-3-ones as starting materials. The reaction of these materials with a suitable reducing agent by the process hereinbefore described affords the corresponding l7ot-alkylandrost-4-ene-3,8,l15,17fi-triols. The acyloxy derivatives of those triols are prepared by the acylation process described above. As a specific example of these processes, 1 lfi,17B-dihydroxy-17a-methylandrost-4-en-3- one is allowed to react with lithium tri(tertiary-butoxy) aluminum hydride in tetrahydrofuran, and the resulting 17a-methylandrostt-ene-3fi,11,8,17fl-triol is contacted with acetic anhydride and pyridine at room temperature to produce 17ot-II16thYlfiI1dI'OSt-4-6I1C-35,115,.17B-t1l01 3-acetate.

A process utilizing 17a,2l-dihydroxypregn-4-ene-3,11, 20-trione -17,21,-diacetate as starting material affords 3- monoacyloxy compounds of the present invention. Thus, that diester is reduced, typically with lithium tri-(tertiarybutoxy) aluminum hydride in tetrahydrofuran, and the resulting 3-hydroxy compound is acylated with the appropriate lower alkanoyl anhydride or halide. Hydrolysis of the 17 and 21 acetate groups is effected by brief contact with dilute methanolic potassium hydroxide, during which treatment the 3-acyloxy group remains intact. The resulting 3B,17ot,2l-trihydroxypregn-4-ene-11,20-dione 3- mono-(lower alkanoate) is stirred with sodium bismuthate in aqueous acetic acid at room temperature to afford the corresponding 3,8-hydroxyandrost-4-ene-l1,17- dione 3-mono-(lower alkanoate). The latter substances are converted to the corresponding l7fi-hydroxy and 11/3, 17,8-dihydroxy compounds of this invention by the aforementioned reduction processes. Thus, reduction of 17a; 21-dihydroxypregn-4-ene-3,lil,20-trione 17,21 diacetate with lithium tri(tertiary-butoxy) aluminum hydride in tetrahydrofuran followed by acetylation of the resulting 35-01 with acetic anhydride and pyridine and saponification of the 17 and 21 acetate groups with methanolic potassium hydroxide afiords 3,8,l7a,2l-trihydroxypregn- 4-ene-ll,20-dione 3-monoacetate. Oxidation with sodium bismuthate affords 3fi-hydroxyandrost-4-ene-11,17-dione 3-acetate. Reduction of that ester with lithium tri-(tertiary-butoxy) aluminum hydride in tetrahydrofuran for two hours yield-s 3,8,17B-dihydroxyandrost-4-en-ll-one 3- acetate, while reaction with excess lithium tri-(tertiarybutoxy) aluminum hydride in tetrahydrofuran for 24-48 hours results in androst-4-ene-3fi,1 1B,l7fi-triol 3-acetate.

The acyloxyandrostane derivatives of the present invention are useful as a result of their valuable pharma cological properties. They are hormonal agents, for example, as is evidenced by their anabolic :and anti-inflammatory properties. In addition, they display potent androgenic activity when administered either intramuscularly or orally.

The invention will appear more fully from the examples which follow. These examples are set forth by way of illustration only and it will be understood that the invention is not to be construed as limited in spirit or in scope by the details contained therein as many modifications in materials and methods will be apparent from this disclosure to those skilled in the art. In these examples, temperatures are given in degrees centigrade C.). Quantities of materials are expressed in parts by weight unless otherwise noted.

Example 1 A mixture of 8 parts of androst-4-ene-3,11,17-trione, 21 parts of lithium tri-(tertiary-butoxy) aluminum hydride, and 178 parts of tetrahydrofuran is stirred at room temperature for about 2 hours, then is poured into approximately 250 parts by volume of 50% aqueous acetic acid. Water is then added to the point of turbidity, and the mixture is extracted with chloroform. The chloroform extract is washed successively with water and dilute aqueous sodium bircarbonate, is dried over anhydrous sodium sulfate, then is concentrated to dryness at reduced pressure. The resulting crystalline product is recrystallized from acetone to afford colorless crystals of 35,176 dihydroxyandrost 4 en 11 one, melting at about 194-197". Another recrystallization from acetone affords pure material melting at about 215218, possessing an optical rotation of +102 in methanol, and displaying infrared absorption maxima at about 2.93, 2.97, 3.38, 5.91, 9.35, 9.62, and 11.70 microns. This compound is characterized further by the structural formula Example 2 The substitution of 8 parts of 115 hydroxyandrost- 4 ene 3,17 dione in the procedure of Example 1 results in androst 4 ene 313,115,178 triol, melting at about 225-226". Two recrystallizations from acetone afford a sample of the pure material melting at about 221-223 and displaying an optical rotation of +84 in methanol.

Example 3 A solution containing 8 parts of 35,1713 dihydroxyandrost 4 en 11 one, 50 parts of acetic anhydride, and 100 parts of pyridine is stored at room temperature for about 17 hours, then is diluted by the slow addition of -a mixture of ice and Water. The precipitate which forms is collected by filtration, is washed on the filter with water, then is dried at about 60 under reduced pressure. The resulting crude product, melting at about 167-170", is 3fl,17fi dihydroxyandrost 4 en 11 one 3,17-diacetate. Further purification is effected by recrystallization from a mixture of acetone and hexane, resulting in material melting at about 174175. This compound is characterized further by an optical rotation of +39 in chloroform, by infrared absorption maxima at about 3.39, 5.75, 5.78, 5.83, 7.96, 9.65, and 9.76 microns, and also by the structural formula (l)COCH3 Q CIIgi Example 4 By substituting 63.7 parts of propionic anhydride and otherwise proceeding according to the processes described in Example 3, 3,8,17/3 dihydroxyandrost 4 en 11- one 3,17-dipropionate is obtained. It can be represented by the structural formula (IJCOCI-IzCHa Example 5 A solution of 2 parts of androst 4 ene 36,115,178 triol, 10 parts of acetic anhydride, and 20 parts of pyridine is heated at about for about 2 hours, then is cooled and diluted with a mixture of ice and water. The resulting crystalline product is collected by filtration, the is washed on the filter with water, and is dried at reduced pressure. Crystallization of this solid material. from methanol affords androst 4 ene 3B,l1fi,17,8- triol 3,17-diacetate, melting at about 142145. A pure sample of this substance, melting at about 152-154, is obtained by recrystallization of the latter material from a mixture of ether and hexane. This compound possesses an optical rotation of +26 in chloroform, exhibits infrared absorption maxima at about 2.88, 3.38, 3.42, 5.75, 5.83, 7.90, 8.08, and 9.56 microns. It is characterized further by the structural formula 0 C O 0 H3 H 0 Ha C 0- Example 6 OCOOHgCH Example 7 A mixture of 9.15 parts of 17,8-acetoxyandrost-4-ene- 3,11-dione, 42 parts of lithium tri-(tertiary-butoxy) aluminum hydride, and 400 parts of tetrahydrofuran is stirred at room temperature for about 48 hours, then is worked up by the procedure described in Example 1 to afford androst-4-ene-3,8,l16,17fl-triol 17-acetate, melting at about -169". Recrystallization from acetonehexane affords the pure substance, melting at about 176 177 and exhibiting an optical rotation of +63 in chloroform. This substance is characterized further by infrared 5 absorption maxima at about 2.75, 2.90, 3.40, 5.78, 7.95, 9.09, and 9.27 microns and also by the structural formula OCOCH Example 8 The substitution of 9.52 parts of 17fi-hydroxyandrost- 4-ene-3,11-dione 17-propionate in the processes described in Example 7 results in androst-4-ene-3/3,1113,17fi-triol 17- propionate of the structural formula OCOCH2CH Example 9 A mixture of 9.16 parts of androst-4-ene-3B,115,175- triol l7-acetate, 63.7 parts of propionic anhydride, and 100 parts of pyridine is kept at room temperature for about 16 hours, then is poured slowly into a mixture of ice and water. The precipitate which forms is collected by filtration, is washed on the filter with water, then is dried at reduced pressure to aiTord androst-4-ene- 35,115,17B4riol 17-acetate, 3-propionate, melting at about 124128. This crude product is further purified by adsorption on a silica gel chromatographic column followed by elution with ethyl acetate in benzene, resulting in material melting at about 138139 and displaying an optical rotation of +25". It is characterized further by the structural formula 0 C 0 CH3 Example A solution of 2.5 parts of 1lB,17/3-dihydroxy-17umethylandrostt-en-3-one, 5 parts of lithium tri-(tertiarybutoxy) aluminum hydride, and 89 parts of tetrahydrofuran is stirred at room temperature for about 2 hours, then is cooled to 05 by means of an ice bath, and is diluted by the slow addition of 100 parts by volume of 20% aqueous acetic acid. The resulting precipitate is collected by filtration, is washed on the filter with water, and is dried under reduced pressure to afford 17a-methyl- O l CHgCH; O

androst-4-ene-3fl,l15,17,8-triol, melting at about 195- 205. Recrystallization from acetone affords the pure material containing one mole of acetone of crystallization, melting at about 20l203, and possessing an optical rotation of +52.5 in methanol. Infrared absorption peaks are observed at about 2.89, 3.05, 3.38, 5.75, 7.75, 9.44, 9.71, and 9.90 microns.

A solution of one part of 17a-methylandrost-4-ene- 3fi,11B,17,8-triol, one part of acetic anhydride, and 5 parts of pyridine is stored at room temperature for about 24 hours, then is diluted with water at about 0. Extrac- 6 tion of this aqueous mixture with chloroform affords an organic solution which is washed successively with dilute hydrochloric acid, water, and dilute aqueous sodium bicarbonate, then is dried over anhydrous magnesium sulfate and concentrated to dryness at reduced pressure. The resulting residue is crystallized from aqueous methanol by allowing the solvent to evaporate slowly, thus affording crystals, which are collected by filtration and dried under reduced pressure at about 60 to yield 17amethylandrost-4-ene-3;8,l15,17fl-triol S-acetate, melting at about 80-85". This crude product is recrystallized from aqueous methanol to afiord the pure material, melting at about 86-88" and displaying an optical rotation of +22.5 in chloroform. Infrared absorption maxima are observed 'at about 2.82, 3.38, 5.75, 7.27, 8.02, 9.20, 9.72,

and 10.15 microns. This compound is further character- I ized by the structural formula -0H Ho Q a Example 1] II CHHCHZC 0- Example 12 The substitution of 9.15 parts of 17,8-hydroxyandrost- 4-ene-3,11-dione 17-acetate in the procedure of Example 1 results in 3/3,17B-dihydroxyandrost-4-en-ll-one l7- acetate of the structural formula OCOCli-Ig GHJ Example 13 A mixture of 6.25 parts of 17a,21-diacetoxypregn-4-ene 3,11,20-trione, 6.25 parts of lithium tri-(tertiary-butoxy) aluminum hydride, and 89 parts of anhydrous tetrahydrofuran is stirred at room temperature for about one hour, then is acidified by the addition of approximately 100 parts of 15 aqueous acetic acid. The chlorofrom solution is separated, washed successively with water and dilute aqueous sodium bicarbonate, then is dried over anhydrous sodium sulfate and distilled to dryness at reduced pressure. The resulting residue is dissolved in a mixture of 20 parts of pyridine and 10 parts of acetic anhydride, then is kept at room temperature for about 16 hours. Dilution with water at about affords an aqueous mixture which is extracted with ether. This ether solution is separated, washed successively with dilute hydrochloric acid, saturated aqueous sodium chloride, and dilute aqueous sodium bicarbonate, then is dried by means of anhydrous sodium sulfate and concentrated to dryness at reduced pressure. The residue is dissolved in benzene and the solution is adsorbed on a silica gel chromatographic column. Elution of the column with 15% ethyl acetate in benzene affords 3 ,8,170:,21-trihydroxypregn-4-ene-1 1,20-dione 3,17,21-triacetate. This material is dissolved in 8 parts of methanol, in a nitrogen atmosphere, and 6.7 parts by volume of 0.8 N potassium hydroxide in methanol is added. After standing for about 4 minutes, 11 parts by volume of 0.9 N acetic acid is added, and the resulting mixture is extracted with chloroform. The organic extract is separated, washed with water, dried by means of anhydrous sodium sulfate, and concentrated to dryness. Crystallization of the resulting residue from ether affords 3fl,l7o ,21- trihydroxypregn-4-ene-l1,20-dione 3-acetate, melting at about ISO-183. Further purification by recrystallization from acetone-hexane affords the pure substance, melting at about 190194 and displaying an optical rotation of +67 in chloroform. Infrared absorption maxima are observed at about 2.73, 2.83, 3.39, 5.81, 7.96, 9.53, 9.75, 10.90, and 11.07 microns. This substance is represented by the structural formula CHaCO- A mixture of 6.5 parts of 36,17a,21-trihydroxypregn- 4-ene-11,20-dione 3-acetate, 1000 parts by volume of 50% aqueous acetic acid, and 100 parts of sodium bismuthate is stirred at room temperature for about 45 minutes, then is filtered through diatomaceous earth. The diatomaceous earth is washed with 50% aqueous acetic acid, and the filtrate is diluted with water, then extracted with chloroform. Successive washings of the chloroform solution with water and dilute aqueous sodium bicarbonate affords an organic solution which is dried by means of anhydrous sodium sulfate, then is concentrated to dryness at reduced pressure. Trituration of the resulting residue with ether affords crystals of 3/3-hydroxyandrost- 4-ene-1l,l7dione 3-acetate, characterized by infrared absorption maxima at about 3.40, 5.77-5.85, 8.02, 8.30, and 9.81 microns.

The substitution of 9.15 parts of 3/3-hydroxyandrost- 4-ene-1l,17-dione 3-acetate in the processes described in 8 Example 1 results in 3 ,8,17e-dihydroxyandrost-4-en-11- one 3-acetate of the structural formula ll CHaC O- Example 1 5 CHzii C Ha C O What is claimed is: 1. A compound of the formula O C-(lower alkyl) ll (lower alkyD-C O- 2. 3,8,17 3-dihydroxyandrost-4-en-1l-one 3,17-diacetate. 3. A compound of the formula CHa l 1 (lower alkyD- 0- 4. Androst-4-ene-3fl,115,17fl-triol 3,17-diaceta-te.

5. Androst-4-ene-3,6,1lfl,l7fl-triol 17-acetate, pionate.

6. Androst-4-ene-3B,115,175-triol 3,17-dipropionate.

7. A compound of the formula 8. Androst-4-ene-3/3,115,17B-triol-17-acetate. 9. A compound of the formula on -(lower alkyl) HO- O (lower alkyl)- O-- 10. 17-methylandrost-4-ene-3B,115,17B-t1'iol 3-acetate. 11. 3B,17fl-dihydroxyandrost-4-en-11one.

12. 3p,17a,21-trihydroXypregn-4-ene-1l,20dione 3-acetate.

13. A compound of the formula OR CH References Cited by the Examiner UNITED STATES PATENTS 11/63 Wettstein et a1. 260-297.5 1/64 Wettstein et a1. 260239.55

OTHER REFERENCES Caspi et 211.: Journ. Chem. Soc. (May 1962), pages 1710-1716 relied on.

LEWIS GOTTS, Primary Examiner. 

13. A COMPOUND OF THE FORMULA 